Note that my post was from Jan 2013, not 2014.
Which site won't let you send e-mail, Horneber or HSM (I.Q.Metals)?
Horneber's e-mail setup (Contact page) also seems to be working OK - at least it will pop up my Thunderbird e-mail client.
I.Q. Metals is effectively "the" HSM website - for quite a while now.
Their brass link is I.Q. Metals Inc. - Brass
Possibly you failed to enter the CAPTCHA.
I just sent an e-mail to IQ asking when they next expect to have 375 CT brass and the e-mail went through just fine.